Occupancy-driven Zeeman suppression and inversion in trapped polariton condensates

TL;DR

This study investigates how magnetic fields influence trapped polariton condensates, revealing Zeeman splitting, its screening, and inversion effects dependent on trap size and condensate density, advancing understanding of spin interactions in quantum fluids.

Contribution

It demonstrates magneto-photoluminescence effects in polariton condensates, including Zeeman splitting, screening, and inversion phenomena, highlighting the role of confinement and interactions.

Findings

Zeeman splitting observed in polariton condensates.

Full parametric screening of Zeeman splitting in small traps.

Complete inversion of Zeeman splitting with power in larger traps.

Abstract

We study the magneto-photoluminescence of an optically trapped exciton-polariton condensate in a planar semiconductor microcavity with multiple In0.08Ga0.92As quantum wells. Extremely high condensate coherence time and continuous control over the polariton confinement are among the advantages provided by optical trapping. This allows us to resolve magnetically induced {\mu}eV fine-energy shifts in the condensate and identify unusual dynamical regions in its parameter space. We observe polariton Zeeman splitting and, in small traps with tight confinement, demonstrate its full parametric screening when the condensate density exceeds a critical value, reminiscent of the spin-Meissner effect. For larger optical traps, we observe a complete inversion in the Zeeman splitting as a function of power, underlining the importance of condensate confinement and interactions with its background reservoir excitons.